WMTS in QGIS: how to get the time steps from the WMTS link?

I generated a WMTS link to display Sentinel-2 time series in QGIS. The “temporal controller” works fine and I can scroll through time easily. This is great.

QGIS temporal controller gives the choice of the time steps (days, weeks, months, …). However, the S2 images do not have a regular time step. If I choose a monthly time step, I miss some images and I do not know which precise date is displayed. If I choose a daily time step, all the days display an image but it is often the same one for consecutive days.

Is there a way to get the WMTS irregular time steps in the temporal controler ?

Complement to my previous post:

I forgot to mention that I configured the WMTS link to be limited over a relatively small area. Therefore, images are present only on specific days.

According to QGIS temporal controller documentation: " Different units are supported, from seconds to centuries . A source timestamps option is also available as step: when selected, this causes the temporal navigation to step between all available time ranges from layers in the project. It’s useful when a project contains layers with non-contiguous available times, such as a WMS-T service which provides images that are available at irregular dates. This option will allow you to only step between time ranges where the next available image is shown."

Is it a bug on QGIS side, a limitation of SentinelHub WMTS, or an error on my side ?